ANN ARBOR—With 36 million followers on Twitter, Indian Prime Minister Narendra Modi is the world's No. 2 most popular politician in the Twittersphere after Donald Trump.

The way Modi uses sarcasm against his opponents is the focus of a new University of Michigan School of Information study that analyzed more than 9,000 tweets by Modi over a six-year period.

"We try and explain what makes him popular," said Joyojeet Pal, U-M assistant professor of information. "Modi's irony provides a form of political spectacle and resonated on social media as shown by high retweeting of his sarcastically worded messages."

Published in the International Journal of Communication, the study examined the Twitter account of Narendra Modi (@narendramodi) to show how he used political irony and sarcasm to become broadly appealing and refashion his political style.

After coding, they found that sarcastic tweets were closely concentrated around election and campaigning cycles."

In many of Modi's tweets during national elections, he referred to the main opposition party as corrupt and Ghandi, its rising leader who also has a huge Twitter following, as "Rahul Baba" or "Shahzada (prince)."

By using humor and sarcasm, he was signaling that the party was not in touch with its roots and letting his own followers get the inside joke, the researchers said.

Here is an example of a Modi tweet, which garnered 2,545 retweets: "The way Rahul Baba is making statements with a dash of comedy in them, I think the TV show of Kapil Sharma may soon have to shut shop."

According to the U-M researchers, Modi's use of sarcasm builds on a longer tradition of slogan humor during political rallies.

Although social media did not reach many of the traditional rural and peri-urban upper caste Hindu voters of Modi's Bharatiya Janata Party, they extended the prime minister's appeal to a new young urban constituency.

"After the election, the sarcasm and mention of Gandhi disappears," Pal said. "Instead, the celebrity mentions and tweets about foreign policy increase dramatically."

According to the researchers, the sarcasm helped separate Hindutva-oriented content, which is traditionally more divisive than the pan-Indian patriotic rhetoric of "India First," through which Modi has gained a more secular standing.

"The power of Modi's message is in the juxtaposition of his past as a train station tea-seller alongside his present as a selfie-clicking leader of a strong aspirational but fundamentally nationalist state," Pal said. "Sarcasm is as much a message from Modi as it is a message about him."